Ørsted was born in Rudkøbing. As a young boy Ørsted developed his interest in science while working for his father, who owned a pharmacy.[4] He and his brother Anders received most of their early education through self-study at home, going to Copenhagen in 1793 to take entrance exams for the University of Copenhagen, where both brothers excelled academically. By 1796 Ørsted had been awarded honors for his papers in both aesthetics and physics. He earned his doctorate in 1799 for a dissertation based on the works of Kant entitled "The Architectonics of Natural Metaphysics".

In 1801 Ørsted received a travel scholarship and public grant which enabled him to spend three years travelling across Europe. In Germany he met Johann Wilhelm Ritter, a physicist who believed there was a connection between electricity and magnetism. This made sense to Ørsted since he believed in Kantian ideas about the unity of nature and that deep relationships existed between natural phenomena.[4]

Their conversations drew Ørsted into the study of physics. He became a professor at the University of Copenhagen in 1806 and continued his research with electric currents and acoustics. Under his guidance the University developed a comprehensive physics and chemistry program and established new laboratories.

In 1800, Alessandro Volta invented a galvanic battery inspiring Ørsted to think about the nature of electricity and to conduct his first electrical experiments. Between 1800 and 1803, he visited to Germany, France and Holland for lectures. Ørsted welcomed William Christopher Zeise to his family home in autumn 1806; taking the then young chemist (and fellow son of a pharmacist) under his care and giving him encouragement while offering him a position as his lecturing assistant. In 1812 he again visited Germany and France after publishing a manual called Videnskaben om Naturens Almindelige Love and Første Indledning til den Almindelige Naturlære (1811). In Berlin he wrote his famous essay on the identity of chemical and electrical forces in which he first stated the connection existing between magnetism and electricity. Then, in Paris he translated that essay in Latin with Marcel de Serres.

The Royal Society of London gave him the Copley Medal and the French Academy awarded him with 3,000 gold francs. Ørsted was just 43 when he made this great discovery. He established the Royal Polytechnic Institute in 1829 of which he was the first director.

On 21 April 1820, during a lecture, Ørsted noticed a compass needle deflected from magnetic north when an electric current from a battery was switched on and off, confirming a direct relationship between electricity and magnetism.[5] His initial interpretation was that magnetic effects radiate from all sides of a wire carrying an electric current, as do light and heat. Three months later he began more intensive investigations and soon thereafter published his findings, showing that an electric current produces a circular magnetic field as it flows through a wire. This discovery was not due to mere chance, since Ørsted had been looking for a relation between electricity and magnetism for several years. The special symmetry of the phenomenon was possibly one of the difficulties that retarded the discovery.[6]

It is sometimes claimed that Italian Gian Domenico Romagnosi was the first person who found a relationship between electricity and magnetism, about two decades before Ørsted's 1820 discovery of electromagnetism. Romagnosi's experiments showed that an electric current from a voltaic pile could deflect a magnetic needle.[7] His researches were published in two Italian newspapers and were largely overlooked by the scientific community.[8]

Ørsted's findings stirred much research into electrodynamics throughout the scientific community, influencing French physicist André-Marie Ampère's developments of a single mathematical formula to represent the magnetic forces between current-carrying conductors. Ørsted's work also represented a major step toward a unified concept of energy.

In 1825, Ørsted made a significant contribution to chemistry by producing aluminium for the first time. While an aluminium-iron alloy had previously been developed by British scientist and inventor Humphry Davy, Ørsted was the first to isolate the element via a reduction of aluminium chloride.

Two medals are awarded in Ørsted's name: the Oersted Medal for notable contributions in the teaching of physics in America, awarded by American Association of Physics Teachers, along with the H. C. Ørsted Medal for Danish scientists, awarded by the Danish Selskabet for Naturlærens Udbredelse (Society for the Dissemination of Natural Science), which Ørsted founded. The H.C. Ørsted Lectureship is awarded to two prominent researchers annually, and has been bestowed upon the following scientists:

Ørsted was a published writer and poet. His poetry series Luftskibet ("The Airship") was inspired by the balloon flights of fellow physicist and stage magician Étienne-Gaspard Robert.[14] Shortly before his death, he submitted a collection of articles for publication under the title "The Soul in Nature". The book presents Ørsted's life philosophy and views on a wide variety of issues.[15]

Bern Dibner (1962) Oersted and the discovery of electromagnetism, New York, Blaisdell.

Ole Immanuel Franksen (1981) H. C. Ørsted – a man of the two cultures, Strandbergs Forlag, Birkerød, Denmark. (Note: Both the original Latin version and the English translation of his 1820 paper "Experiments on the effect of a current of electricity on the magnetic needle" can be found in this book.)